US977285A - Expanded metal bar or member. - Google Patents

Description

K. DYSON. EXPANDED METAL BAR OR- MEMBER. APPLICATION FILED umza. 1909.

97?,285, Patented Nov. 29, 1910.

XXIX X s UNITED STATES PATENT orinon.

HERBERT KEMPTON DYSON, F FIiVSBUBY PARK, ENGLAND;

L EXPANDED METAL BAR 0R MEMBER.

Application filed January 28, 1909. Serial No. 474,737.

To all 'w7wm it may concern:

Be it known that I, Hnnnan'r KEMP'ron Dyson, a subject of the King of Great Brit.-

o vements in and Relating to Ex anded ain, residing at 73 Digby'road, Finsbury Park, in the county of Middlesex, En land, have invented certain new and usefu Inietal Bars or Members, of which the ollow ing is a specification.

This invention relates to expanded metal bars or members for reinforcing concrete and has reference to the type of bar or member that'is expanded at its ends so as to comprise upper and lower members connected by expanded metal strips.

The chief object of the present invention is to provide an improved metal bar or member of this ty e capable of being easily manufactured an ada ted for general use in structures, particu arly for reinforced con- ,resist the compressive stresses althou h sometimes it is assisted in this respect by t as metal reinforcement. Before describing my invention I will demonstrate what appears to me 'to be the manner'in which the stresses are distributed in a reinforced concrete beam 2 shown in h a.

which stresses in my view' are distributed in an analogous manner to that of a trellis girder.

Figure 1 is a diagram of a trellis girder drawn to illustrate the stresses therein when loaded. Fig. 2 represents diagrammatically the distribution which the metal should have to accord with my view. Fig. 3 is an en larged cross section of a bar of metal suitable for expansion according to my. invention. Fig. 4 is a length of metal slit diagonally with an unslit portion in the middle, Fig. 5 being similar'to Fig. 4 except that the slitting of the metal is continuous throughout its length. Fig. 5 shows in plan and to a larger scale the bar shown in Fig. Fig. 6 re resents a bar of metal expanded in accor ance with'my invention after being slit as shown in Flg. 4. Fig. 7 isslmilarfto Fig.

6, showin the expansion of'a bar such as Fig. 8 is similar to F 1g. 7

.1. with .the exception that certain of the strands or shits have been turned up 'iattios Specification of Letters Patent.

Patented Nov. 29, 1910.

Referring first to Figs. 1 and 2, it will be seen that Fig. 1 shows in diagrammatic form thenature of the stresses in the ,vertical and horizontal members of a trellis girder supported at the middleand freely supported at the ends. members in tension and the thick lines members in compression. Now in a reinforced concrete beam the concrete will resist the compressivestresses-except those that. are

The thin lines show.

very considerable, such as occur at the lower side of the beam over the central support at which point the concrete should be assisted by metaland the metal, usually steel, takes the tensile stresses.

When reinforced concrete beams have their ends built in, as they usually are in practice, horizontal reinforcements are required at the top of the beam at these ends so as to resist the reverse bending moment,

while the compression becomes so great below that steel must be introduced there also. Rolling loads cause a reversal of stresses in the diagonals at the center of each span and toresist these stresses latticed tension web members are required in beams of large span. Theoretically therefore, the correct disposal of reinforcements for a reinforced concrete beam built in at the ends I believe to be the form shown diagrammatically in Fig. 2.

According to my invention I take a flanged metal bar of any convenient shape in section, and I slit the intermediate web portion of this bar the whole or only part or parts of the length along lines runn ng diagonally, that is ,to say at an inclination to thelongitudinal axis pf the bar and at very acute angles so as to leave two, three or more strands or slats side by side. At one end of the bar I then bend or crank up a convenient length of one of thefianges out of the plane of the bar-and away from the other flange so as to separate the aforesaid strands or slats into an open framework in which they are inclined dia onally to the horizontal top andbottom anges, and at the other end I also bend orcrank up a convenient length of one of the flanges so as to separate the strands or slats in an oppositely inclined direction to those at the other end. The intermediate portion of the bar remains unexpanded. If the Web has been slit into strands or slats alon the whole length of the bar and if it is esired'to raise any of thestrandsnr slats at tiie intermediatoportion of the bar. without bending the flanges I sever their ends alternately at the junction with the flanges, and bendthem up so that they cross each other lattice-wise in oppositely inclined directions. By altering the. angle at which the diagonal slits meetthe flanges and by altering the distances they are apart the vertical members can be made priate length as shown in Fig. 6, an

longer or shorter and with various widths and spacings between them, as may be desired. I prefer the diagonal slits to be inclined all iii the same direction at a small angle with the longitudinal axis of the bar and to be cut so that two or more strands or slats-lie side by side for part of their length.

One advantage of slitting diagonally is that two or more slats or strands can be arranged'tolie side by side for part of their length as above stated, the result being that the length of the slats or strands does not necessarily determine the height to which one flange can be raised to expand the bar as is the case when a single row of'slats or strands is formed merely in succession along the web portion, in such a way that, one slat ends before the next begins.

A further advantage of slitting the bar diagonally resides'in the fact that such can be expeditiously done by merely passing the web portion under a roller or between rollers having one or more helical cuttingf'tidges on the surface of the same.

In order that my said invention may be clearly understood and readily carried-into, effect, I will proceed to describe the same. more fully with reference to Figs. 3 to 8. The bar comprises the Web or strip A and the flanges B and B. A long banof metal, as it comes from the rolling mill dit diagonally, may be cut up into sections of the required length with slanting extremities as shown in Figs. 4, 5 and 5. The flange B at the end at which it extends beyond the flange B is cranked or raised up for an a pr}?- t e projecting flange B at the 1 other end is similarly cranked or raised up, theJQsult being that the strands or slats C constituted by the slit portio s of the metal are inclined in opposite directions at the two ends. In cases where the bar is slit for the whole of its length, as it would usually be in practice to avoid the necessity of discontinuing the slitting operation, the strands or slats C in the central portion may be turned up latticewise as shown in Fig. 8. These lattice slats help to reinforce a beam against rolling loads. An advantage of shearing the ends of the sections slantwise as shown in Figs. 4, 5 and 5 is that when the bar is expanded the longer flange is bent back so that its end measured from the middle of the central or unexpanded portion of the bar is at approximately the same distance from the middle I of the bar as the end of the other flange. i The angle at which the ends of the bars are sheared may of course be varied to .suit the are to be used.

It will be understood that if the diagonal slitting of the metal was such that the direc tion of the slitting at one end of the bar was in theopposite direction to that at the other end, the cranking up or separation of the flanges at the ends of the bar would be performed by raising the same flange at each end, as it will be seen that this'would cause the strands or slats to be oppositely inclined in the same manner as above described.

I, What, I claim and desire to secure by Let-. ters Patent of the United States is 1. An expanded metal member formed from a bar having flanged edges-and the web portions slit into a sin le row of parallel strands each inclined to t e longitudinal axis of the bar, and comprising end portions expanded in a plane transverse to that of the bar, and each comprising an upper and lower flanged edge connected by inclined strands slitted webportion, the strands 'in the aforesaid end portions being oppositely inclined and the flanged edges continuous throughout the length ofthe bar. J"

'2. An expanded metal member formed froma bar having flanged edges and a web -portion diagonally slit throughout and comprising a middle portion having the'strands formed by the slitted web portion each severed at one end and turned up transverse to theplane of the bar, and end portions expended in a plane transverse to that of the er and each comprising an up er and lower flanged edge connected by inc ined strands formed from the expansion of the diagonally slitted web portion, the strands in the aforesaid-end portions being oppositely inclined.

3. An expanded metal memberformed from a bar having flan ed edges and a. web portion slitted diagonally throughout, and comprising a middle portion having the strands formedjby the slitted Web portion severed at alternate ends and. turned up latandend portions ex anded in a plane transverse to that of the, at and each comprisin an up er and lower flanged edge connected by inc ined strands formed from the expanslon of the diagonally 'slitted-web ortion, the strands in the aforesaid end port ons being 0 positely inclined. g

4. expanded -metal member formed from a bar having flanged edges and a 'web portion slitted into a single row of ara'llel strands, each inclinednto ,the longitudinal expanded in a lane transverse to that of the bar and'eac comprising an up er and lower flanged edge connected by inclined formed from the expansion of the diagonally ticewise transverseto the plane of the bar, a.

ditlerent circumstances under which the bars axis of the bar, and comprising end portions strands formed from the expansion of the slitted web port-ion, the upper flanged edge at one end being formed by'bending up one of the flanged edges of the bar out of the plane of the bar, and the upper flanged edge at the opposite end being formed by bending the other flanged edge out of the plane of the bar, said bent edges being continuous with the remaining unbent portions of said flanged edges. I

5. An expanded 'metal member formed from a bar having flanged edges and a eb portion slitted diagonally in the same direction throughout, and-comprising a middle portion having the strands formed by the slitted web portion severed at one endand turned'up transverse to the plane of the bar,

and end portions expanded in a plane trans-" verse to that of the bar and each eomprisin an upper and lower flanged edge connected by inclined strands formed from the expansion of the diagonally slitted Web portion the upper flanged edge at one end bein termed by bending up one of the flanged edges of the bar out of the plane of the bar,

and the upper-flanged edge at the opposite end being formed by bending the other flanged edge out of the plane of the bar.

. -(5. An expanded metal member formed from a bar having flanged edges and a Web portion slitted diagonally in the same directidn throughout, and-comprising a middle portion having the strands formed by the slitted web portionv severed at alternate ends bar. 7. A bar from which to form an expanded metal member, said bar comprising two flanged edges and a Web portion slitted to 'form parallel strands each inclined to the longitudinal axisof the bar, the ends of the bar being sheared slantwise for the purpose specified. y

8. A bar from which to form an expanded metal member, said bar comprising two flanged edges and a Web portion slit-ted to form parallel overlapping strands each inclined to the longitudinal axis of the bar, the

ends of the bar being sheared slantwise for the purpose specified.

In testimony whereof I afiix my sign'atur in presence of two Witnesses.

HERBERT KEMPTON DrsoN.

Witnesses lVAL'rER J ,SKERTEN, T. SELBY WARDLE.

the other flanged edge out of the plane of the

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